| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] have [vb pp] [art] | 124 |
|
| 2 | could have [vb pp] [art] [adj -er] | 21 |
|
| 3 | [adv] have [vb pp] [art] [adj -er] | 18 |
|
